1. Field of the Invention
The present invention relates to a cutting unit for producing a road marking, having a rotary unit, rotatable about a rotation axis, that can receive a plurality of cutting elements that define a cutting curve, the cutting curve forming a convex cutting region in the direction of the rotation axis.
The invention further relates to a road marking having multiple depressions introduced into the road surface, the depressions comprising two lateral longitudinal walls, extending in the longitudinal direction of the road, that transition, proceeding from the road surface, into a bottom region; and the depression being delimited by two transverse walls extending transversely to the longitudinal direction of the road. Such road markings are also referred to as “rumble strips.”
2. Description of the Prior Art
U.S. Pat. No. 6,547,484 B2 discloses a road milling machine having a cutting unit that comprises a tubular milling drum as a rotary unit. The drum surface is barrel-shaped and is curved convexly in the direction of the rotation axis. It receives cutting bit holders in which cutting bits can be replaceably received. The cutting bits are equipped with carbide metal tips that serve as cutting elements. Corresponding to the convex curvature of the drum surface, the carbide metal tips form a convex cutting curve in the direction of the rotation axis of the milling drum. This convex cutting curve results during rotation of the rotary unit. When the rotating cutting unit is advanced in the direction of the road surface to be processed, the cutting bits then cut a depression out of the road. Corresponding to the convex curvature of the cutting curve, a concave recess is correspondingly produced transversely to the longitudinal extension of the road. Because of the circular cross section of the rotary unit, the depression has a concave shape in the longitudinal extension as well. In order to produce a road marking, multiple depressions are milled into the road, distanced from one another at identical spacing. The road marking thus forms a deliberate geometrical irregularity in the road. When it is rolled over by a vehicle tire, noise and vibrations occur which are perceived by the driver and notify him or her, for example, of a departure from the road.
The road markings thus have the function and object of delivering an acoustic and haptic warning signal. This noise source is, however, on occasion perceived as disruptive by the surroundings adjacent to the road. A further disadvantage of the known road markings results when they are driven over by a two-wheeled vehicle. The two-wheeled vehicle is laterally offset in that context, which can then trigger dangerous steering corrections by the driver. When rainwater collects in the depressions, the driving situation of the two-wheeled vehicle can then additionally become unstable.